Ribbon reverse for typewriters and like machines



Sept. 13, 1932. p. KAPPLER 1,876,687

RIBBON REVERSE FOR TYPEWRITERS AND LIKE MACHINES Filed Nov. 19, 1927 2 Sheets-Sheet i RuenZar sqfli. 13, 1932. v KA R 1,876,687

RIBBON REVERSE FOR TYPEWRITERS AND LIKE MACHINES Filed Nov. 19. 1927 2 Sheets-Sheet 2 /7' z uen for,

Patented Sept. 13, 1932 T mur. glimmer niaEsDEiv, GERMANY iun'iaon nnvnnsn roRfTYnnwnr'rnRs "AND L-rKE MACHINES Application filed iioveliit'er ef eaz, serial No.

i known manner by the direct action of the ribbon tension without the useof feeler levers or ribbon attachments. The device of the present inventionisdis tinguished-from such known devices by'its particular simplicity and reliable action, by the absence of any stops for the ribbon lifter, and by the prevention of damage to the -rib bon. f .v

The device in the embodiment of the inven'- tion as herein-disclosed comprises a cam which is caused by'the tension on the band to press orrub againsta collar" on theribbon' feed shaft in such a'manner that therotation of the feed shaft caused by depression of a key helps to turn the cam,"s o thatthe feed shaft is shiftedfor a ribbon reversal by the cam alone. It is therefore only necessary that the ribbon tension should be sufficient to hold thecam in contact with the collar on the shaft, whilst the main power for displacing the shaft axially to reverse the ribbon feed is derived from the depression of the keys.

an The accompanying drawings illustrate one embodiment of the invention by way of example.

Fig. 1 is a front view of the ribbon mecha nism partly in section. Fig. 2 is a plan view and Fig. thereof. I

The two ribbon spools 1 and 2 are fitted upon the vertical spindles 3 and 1 so as to rotate therewith, the lower ends of the spin- 49 dles carrying the bevel wheels 5 and 6 respectively, which intermesh with bevel wheels 7 and 8 on a ribbon feed shaft 9. The shaft 9 is journalled in the machine frame'lO and is driven from the universal bar of the machine in the usual manner by a pawl 11 and ratchet wheel 12. The shaft 9 is held against accidental axial movement by a spring-controlled catch not shown on the drawings.

The ribbon 24 is guided at the printing point by the swinging movement of the rib- 3 a side view rotate throughthe space of one'to'o'th of the 234,306, and in Germany November 27, 1926.

. bon fork 13, and is alsoguided'by rollers 14 j and l5whose journal pins arefixed on actuating arms 16 and 17 controlled by springs 25 and'26. The arms 16 and 17 are fixedto rock shafts 18 and 19 respectively, which also carry shifter'calns or curved plates 20 and-21; The latter {cooperate with collars 22 and 23"on the shaftgyjf 1 The operation of the device is as f'ollows-:

I '"As shown'in Fig. 2, the ribbon 2 1" 'is'be'ing 9 wound on to the right-hand spool 2 and un wound from theleft-han'd spool 1. When the ribbon from the spool 1 is spent, the ribbon becomes taut because the shaft 9 con-tinuesto ratchet wheel'12 every time'a key is depressed; The. spring 25 .which controls the arm 16 is no longer' ableto'hold thefroller'l f in the position shown in full linesagainst the ribbonten'sion', and the 'roller lt'is' forced by the ribbon int 'the' dotted position. The ribbon tension hashoweve'rino influence on the righthand roller 15, because thearmjl'l' is so dis-' posed asto hold the'ribbon tangential to the fully-wound spool 2. When the roller 14-.is nioved from the position shown in full lines tothe dotted position, the curvedplate 20 nio'ves' in the opposite directionand touches or-rubs agains'tthe collar 22 0f the shaft 9 q at' a""point above the shaft 9, thatfis to say, where the collar 22' with each stepwise rotation of the shaft '9, moves in the same direc; ti'on, viz backwards, as is themov'ement' of the cam plate 20. By this means, the friction betweenthe two parts is usefully employed and the rotation of the shaft 9'eifected'by'depassion-pr a key is substantially utilized'in conjunction therewithto' displace the shaft 9 until the bevel wheel7 meshes with thebevel W wheel 5. When this occurs, thetension on i theribbon is completely relieved and the arm 1 6 is again brought into itsnormal position bythe spring 25. Y l .l-claimifl 7 "f1. Ribbon-mechanism comprising a pair of' ribbon spoolsupon which a ribbon is wound and unwound, spindles carrying said spools, gear wheels on said spindles,.a .rotat ble n.d, axial ym e d haf ear- IOU ing on said shaft adapted in one position of the shaft to drive one of said spindles and in th other position of .said shaft to drive the other of said spindles, means for intermittently rotating said shaft, a pair of collars fixed on said shaft, an element movable into the path of each of said collars so as to form an abutment and having a cam surface for engagement by the collar on rotation of the shaft to shift said shaft axially, and

spring-controlled members held in contact said shaft, a cam cooperating with each of said collars, vertical shaftson which said cams are mounted, an arm projecting from each vertical shaft, a roller carried by said arm,-and a spring for holding said roller in contact with the ribbon and for normally holding said cam out of engagement with the cooperating collar. H j 3. Ribbon mechanism comprising a pair of ribbon spools, spindles carrying said spools, a rotatable and axiallymovable feed shaft, sets of gearing whereby said spindles are alternately driven by axially shifting said shaft in opposite directions, means for intermittently rotating said shaft,'an abutment fixed to the shaft adjacent to each set of gearing,and an abutment adjacent to each spool shiftable by the tension of a portion of a ribbon when spent from said spool into direct engagement with the abutment on the shaft adjacent to the set of drive gearing on said spool, said shiftable abutment; having a surface operative on rotation of the coact ing shaft abutment with the shaft to shift said shaft abutment and shaft axially toward the other set of drive gearing and related abutments. V

4. In a ribbon mechanism for typewriters, ribbon carrying spools, and a ribbonfeed and reversing mechanism including a rotary and longitudinally shiftable feed shaft, an

abutment on the shaft, and a swinging member movable on ribbon exhaust from a spool transversely of the shaft and carrying a cam movable therewith to lie in the path of said abutment, said cam having a curved surface against which the abutment directly wipes on rotation of the shaft for shifting the shaft for a reversing action. I

5. In a ribbon mechanism for typewriters, ribbon carrying spools, ribbon feed and 'reversing mechanism including a rotary and longitudinally shiftable feed and reversing shaft, an abutment on the shaft, a spring retracted swinging shift lever having a contact to engage a ribbon adjacent to a spool and arranged to hold the intervening portion of the ribbon tangentially to the periphery of the spool, said lever being movable for a shifting action in the direction of the ribbon feed under the tension of a final portion ofthe ribbon unwinding from the spool, and a member movable by said movement of the lever into the path of said abutment and having a surface directly engaged by said abutment on a rotary movement of the shaft to shift the latter for a reversing action.

6. In a ribbon mechanism for typewriters, ribbon carryingspools, aribbon wound on said spools and having its ends fastened to respective'spools, ribbon feed and reversing mechanism including a rotary and longitudinally shiftable feed and reversing shaft, an abutment on the shaft, a spring-retracted swinging shift lever arranged to engage a ribbon adjacent to a spool and to hold the intervening portion of the ribbon tangentiallyto the periphery of therspool, said lever being movable for a shifting action under the tension ofthe ribbon against its fastening to a spool upon a final portion of the ribbon unwin dingfrom the spool, and a shoe movable by said movement of the lever into the path of said abutment on a rotary move: ment of the shaft to shift the latter for a reversing action. PAUL KAPPLER. 

